The coefficient of performance (COP) of air-conditioning systems is inversely
proportional to the temperature lift between evaporator and condenser. For the
reduction of this temperature lift, faster heat rejection methods need to be explored.
Evaporative cooling of the air-cooled condensers with water spray is identified as one
of the techniques for this category of condensers. A detailed theoretical model was
developed to study the heat and mass transfer characteristics of unfinned (bare) and
finned evaporatively-cooled condensers of air-conditioners under different operating
conditions. A 5.8 kW capacity split air-conditioner was modified to incorporate the
evaporative cooling and experiments were performed. The detailed theoretical model
has been validated using the experimental results. A simplified model was also
developed and its numerical results compared with the detailed model and
experimental results. A brief analysis on the benefits and potential challenges in the
implementation of evaporatively-cooled condensers in the Singapore context has also
been performed.